Air conditioning system



Nov. 22, 1938. R, B, P CRAWFORD 2,137,996

AIR CONDITIONING SYSTEM Original Filed July 5, 1929 11 Sheeis-Sheet 1 Nov. 22, 1938. R B p CRAWFORD 2,137,996

AIR CONDITIONING SYSTEM Original FiledIJuly 5, 1929 ll Sheets-Sheet 2 1938- R. B. P. CRAWFORD 2,137,996

AIR CONDITIONING SYSTEM Original Filed July 5, 1929 ll Sheets-Sheet 3 55 iii/77672 BL owfR AIR CONDITIONING SYSTEM Original Filed July 5, 1929 ll Sheets-Sheet 4 HFHTEIZ Nov. 22, 1938. R. B. P. CRAWFORD 2,137,996

AIR CONDITIONING SYSTEM Original Filed July 5, 1929 11 Sheets-Sheet 5 BL OWf/E PUMP Nov. 22, 1938. R, p CRAWFORD 2,137,996

AIR CONDITIONING SYSTEM Original Filed July 5, 1929 ll Sheets-Sheet 6 @fl ang AIM paw Nov. 22, 1938.

Original Filed July 5, 1928 R. B. P. CRAWFORD AIR CONDITIONING SYSTEM 11 Sheets-Sheet '7 Nov. 22, 1938. R p. CRAWFORD 2,137,996

AIR CONDITIONING SYSTEM Original Filed July 5, 1929 ll Sheets-Sheet 8 1938. R. B. P. CRAWFORD 2,137,996

AIR CONDITIONING SYSTEM Origifial Filed July 5, 1929 ll Sheet-Sheet 9 NOV. 22, 1938. 5 (:RAWFORD 2,137,996

AIR CONDITIONING SYSTEM Original Filed July 5, 1929 ll Sheets-Sheet l0 HEHTEE Nov. 22, 1938. R. B. P. CRAWFORD AIR CONDITIONING SYSTEM Original Filed July 5, 1929 ll Sheets-Sheet 11 amen M foaf/er 5 P C BAH/FORD,

SUM

Patented Nov. 22, 1938' PATENT OFFICE AIR CONDITIONING SYSTEM Robert B. P. Crawford. signor to Frick Comp Washington, D. 0., asany, Waynesbo'ro, Pm, a

corporation of Pennsylvania Application July 5, 1929, Serial No. 375,952 Renewed June 10, 1938 45 Claims.

This invention relates to air conditioning systems and more particularly to the method of and apparatus for maintaining the required humidity and temperature conditions in such systems along with special treatments applied particularly to recirculated-air as will be disclosed hereinafter in detail.

The present invention is shown as used in connection with incubating and brooding apparatus such as is used on poultry farms for hatching eggs and brooding chicks, and has as its general object to provide improved methods and apparatus for governing the conditions under which the incubating and brooding operations occur, to the end of increasing the yield of healthy chicks from a given quantity of fertile eggs. The steps of incubating and hatching are so closely related, the one immediately following the other in the period of incubation of the egg, that, insofar as certain broad features of the invention are concerned, they may be regarded as the same, and the same is also true of the steps of hatching and brooding, while with reference to other more specific features of the invention the operations of incubating, hatching and brooding are three entirely distinctive steps calling for diflerent apparatus and a difierent treatment of conditions in association with each, as will be pointed out at greater length in the detail description of my invention.

Owing to the large scale operations under which incubating and brooding is now carried on, wherein thousands of eggs are frequently handled in a single hatch, it is now being realized that for the greatest hatching yield consideration must be given to factors which were hitherto not appreciated or were totally ignored. In order that the highest efliciency may be obtained in the incubating, hatching and brooding enclosures, I have found that consideration must be given to the following conditioning factors: (1) The maintenance of the proper temperature; (2) the maintenance of the proper humidity; (3) the supplying of the requisite oxyge (4) the dissipation or removal of carbon di xid and other gases emitted from the eggs; (5) the supplying of a bactericidal agent, such being highly desirable, although not essential; and (6) the removal of fluif picked up by the air currents from the bodies of the chicks, such also being highly desirable, although not essential.

Eggs in their early stages of incubation require the supplying of an appreciable amount of heat thereto, and, hence, the air contacting with these eggs must be at a suificiently high temperature to supply this heat. On the other hand, eggs in the advanced stage of incubation generate and emit heat, and care must be taken that the air contacting with these eggs does not allow them to become overheated. It will therefore be seen that the maintenance of the proper temperature is critical, where maximum incubating efliciency is desired, and the circulation of this air is also important for the avoidance of hot spots in the incubating enclosure.

Still further, the temperature of the air supplied to the hatched chicks should preferably be considerably lower than the temperature of the air circulated through the eggs.

With reference to humidity, it is desirable that such be maintained at an approximately constant percentage, or within certain limits. Moreover, the relative humidity of the air in the incubating egg enclosure should preferably be of a different value than the relative humidity of the air in the chick enclosure.

Eggs in the advanced stage of incubationgive ofi considerable carbon dioxid, and these eggs must be supplied with additional oxygen. The carbon dioxid emitted from these eggs in the 5 advanced stage of incubation, and from the chicks, must be effectively removed from the air for maximum incubating and brooding efiiciency. The use of a bactericidal agent is a preferred step in my improved method for preventing the growth 3 of bacteria. According to one method'the invention contemplates the use of ozone or formaldehyde as the bactericidal agent, and preferably supplies such agent to the different enclosures in different proportions, represented by an inhibit- 35 ing or weak concentration in one case, and by a killing or strong concentration in another case. According to an alternative or supplementary method, the circulating air is brought into contact with a purifying circulation of liquid in the conditioning apparatus.

Based upon the foregoing, the invention has as one of its principal objects to provide an improved method of and apparatus for conditioning the incubating, hatching and brooding enclosures whereby all of the above conditioning factors are properly taken care of and are properly'r'egulated in accordance with the particular requirements of the enclosure.

A further object of the invention is to provide incubating and hatching apparatus which can be substantially closed to atmosphere and wherein substantially the same charge of air is recirculated continuously through the apparatus. In this continuously repeated cycle of circulation 55 2 l aromas such volume of air is repeatedly reconditioned as to humidity, temperature, the removal of. carbon dloxid, the removal of fluff, the replenishment of oxygen, and the supplying of a bactericidal agent. By virtue of the fact that the air circuit can be substantially closed to atmosphere, the above conditioning factorscan more easily be maintained at fixed definite values, such being of particular importance 'as regards temperature and humidity, which are thus substantially isolated from the influence of temperature and humidity variations of outside atmosphere. Such substantial isolation of the volume of condition ing air from outside influences enables the temperature and humidity of the conditioning air to be maintained at the desired values with aminimum expenditure of energy. In its continuously repeated circulation in the system, this volume of conditioning air functions as a vehicle or conveying medium for conveying the proper temperature to or from the eggs, and chicks; for conveying the proper humidity to the eggs and chicks; for conveying the carbon dioxide from the eggs and chicks to a point of dissipation from the system; for conveying oxygen and a bactericidal agent to the eggs and chicks; and for conveying flufl from the chicks to a point of fluff removal.

As above remarked, numerous advantages accrue to the ability to substantially seal or close the air circuit from the atmosphere, avoiding those temperature and humidity losses and fiuctuations which are always incident to the use of fresh air inlets and foul air vents, and in most embodiments of the present invention the air circuit is thus closed from the atmosphere. However, the invention is not limited to this specific arrangement, and in fact I have shown some embodiments where the air circuit or the enclosure has communication with the atmosphere, such being particularly adaptable, for example, to brooders wherein the conditioning requirements as to temperature and humidity are not -.-so exacting as in incubating and hatching enclosures.

A further object of the invention is to provide an improved method of reducing the temperature of the spray water for the conditioning apparatus, comprising the novel step of utilizing an outside cooling tower and thus avoiding the expense and care of operation of refrigerating apparatus or the supplying of cooler city water. In this regard, another object of the invention is to provide an improved method of dissipating carbon dioxid and other objectionable gases to the atmosphere while still retaining the circuit of the conditioning air substantially closed to atmosphere.

A further object is to provide an improved conditioning system wherein the installation cost and the operating expenses are kept low by a unique method of heat interchange and humidity interchange between the difierent enclosures of the system. A further object is to provide a conditioning system ofthe above general description wherein practically all of the controlling and regulating operations are performed automatically.

Other objects and advantages of the invention will appear in the following description, disclosing one preferred manner of carrying my invention into efi'ect'. In the drawings accompanying this description:-

Fig. 1 is a plan view of an incubating and hatching enclosure to which my invention has been applied, with the upper portion partly broken away;

Fig. 2 is a side view thereof, partly in longituginal section on the plane of the line 2-4 of Fig. 3 is a view similar to Fig. 1, of an enclosure wherein the air supplied to the hatching eggs is handled separately from the air supplied to the incubating eggs;

Fig. 4 is a transverse sectional view through this latter embodiment, taken approximately on the plane of the line 4-4 of Fig. 3;

Fig. 5 is a vertical sectional view through a relatively simple form of conditioning apparatus arranged for handling a single volume or quantity of air;

Fig. 5A is a detail figure showing a modified construction of the conditioning apparatus illustrated in Fig. 5;

Fig. 6 is a similar sectional view through another embodiment of conditioning apparatus for handling a single volume or quantity of air, the electrical control circuits thereof being illustrated diagrammatically;

Fig. 6A is a fragmentary diagram of the circuits of the control relays illustrated in Fig. 6;

Fig. 'l is another vertical sectional view through a modified embodiment of conditioning apparatus handling two separate volumes or quantities of air, and illustrating the humidity controlling or transferring communication between the two portions of the system;

Fig. 8 is a vertical sectional view through another modified embodiment of conditioning apparatus, the control apparatus therefor being illustrated diagrammatically;

Fig. 8A is a vertical sectional detail view of refrigerating apparatus for cooling the spray water and also a control valve for introducing cold water to the circulating system;

Fig. 8B is a fragmentary diagram of a modified arrangement of the pressure controlled blower means illustrated in Fig. 8;

Figs. 9, 10, 11, 12, 13 and 14 are diagrammatic views illustrating adaptations of my invention to a plurality of enclosure units;

Fig. 15 is a diagrammatic view of an embodiment wherein water is circulated through the.

enclosure;

Figs. 16 and 17 are similar views showing modified arrangements thereof; and

Fig. 18 is an illustration, partly in section, of an embodiment employing two conditioning devices, and adaptable to ,the conditioning of different types of enclosures calling for different conditioning requirements.

Referring first to Figs. 1 and 2, an incubating enclosure is generally indicated at I. The eggs undergoing incubation are supported in stacks of superposed trays 2| which may be grouped in any preferred relation in the incubator.

In the arrangement shown, the trays are grouped in a tier or tiers extending centrally of the enclosure, whereby an aisle 22 is provided at each side of the stacker tier, from which aisles access may conveniently be had to the trays from opposite sides of the stack. Entrance doors 23 are provided for the aisles 22 at one end of the enclosure. The egg supporting trays are usually mounted on tiltable supporting means whereby the trays may be tilted periodically to turn the eggs, the details of such tilting mechanism in and of themselves forming no part of the present invention. A false ceiling 25 spaced from the roof of the enclosure defines an upper will be understood that the bottom of the trays 2| are of openwork or mesh construction so that the ascending current of air will have intimate contact with all of the eggs. a 7

During incubation the eggs are periodically moved as stated above and when the eggs are I being tilted it is convenient and desirable to pro:

gressively move the trays from one position to another in the tiers, from one tier to another, as when the eggs reach the hatching period, or otherwise. When the eggs reach the hatching stage, the trays containing the same may be shifted to another portion of the tier or to any other part of the enclosure, or such trays may be allowed to remain in the positions to which they have been progressively moved during the incubating period.

In the disclosure illustrated in Figs. 1 and 2 the same volume or quantity of air which is circulated in contact with the eggs in process of incubation is also circulated in contact with the eggs which have reached the hatching stage. The air ascending into the upper plenum chamber 26 is circulated longitudinally thereof into a duct 34 leading to the upper end of a conditioning unit Cl disposed at the end of the incubating enclosure I.

Referring to Fig. 5, such conditioning unit comprises a casing 4| having its interior divided into three vertical passageways 42, 43 and 44 by the two vertical partitions 45 and 45. A transverse partition closes the upper ends of the two passageways 43 and 44. The air entering through the duct 34 passes downwardly through the chamber area or passageway 42, first encountering a find removing screen 48 extending across the upper end of the passageway 42. The mesh of this screen is sufficiently fine to catch all of the light feathery flufl' picked up by the air rising through the hatching trays. The screen has tray flanges around its perimeter which slide upon angle iron supporting brackets 49, the front or side wall of the casing having a normally closed opening through which the screen can be Withdrawn for cleaning.

The air then passes through a spray zone created by spray apparatus S comprising nozzles 52 projecting outwardly from a vertical spray pipe 53. The upper nozzles discharge upwardly against the screen 48 and the lower nozzles discharge downwardly, although such arrangement is not essential.

The air then passes around the lower end of the partition 45 and upwardly into the intermediate passageway 43, where it enters another spray zone created by the discharge from nozzles 52' projecting from a branch spray pipe 53. Some of the latter nozzles are preferably directed upwardly so that part of the spray is upwardly and part downwardly. The precipitated spray water accumulates in a reservoir or tank 54 formed at the lower ends of the passageways 42 and 43 by a transverse plate 55 extending between the side wall of the casing and the partition 46. The main spray pipe 53 extends down through the water tank 54 and connects with the outlet of a pump P disposed below the water tank. The pump is driven by an electric motor description of the control circuits.

. 58, also disposed in this lower pump compartment of the casing. A return pipe 59 leads downwardly from the bottom of the tank 54 and communicates with the inlet to the pump P, the upper end of such return pipe being preferably closed over by a straining screen 5| to prevent foreign matter being circulated by the pump.

Such water as is .taken up by the air in the humidification of the latter is replenished from,

an outside source of supply connecting with the pump or with the tank 54 through a suitable float closed opening through which such container can be withdrawn for replenishing the lime supply.

The spray water in precipitating down over th lime in the container 58 carries some of this lime in solution up to the spray jets 52. 52 where it is projected into the air. The removal of substantially all carbon dioxid' from the air occurs along with the humidification of the air in the two spray zones 42 and 43, by virtue of the higher partial pressure of the carbon dioxid resulting in absorption thereof by the spray water, and also by virtue of the direct vcontact of the air with the lime in the container 68, as will be hereinafter described in more detail.

Extending across the upper portion of the intermediate passageway 43 is a series of baiiles H which prevent the spray from passing upwardly out of the upper end of said passageway, and which also function to scrub the air and remove excess, unvaporized water therefrom. Projecting into such baffles is a thermostat H, of any desired type, which governs the humidity of the air, as will be presently described. After passing up through the baffles II the air is deflected laterally and passes through an electric heater 13, from whence it enters the upper end of the third passageway 44. This heater is controlled by a thermostat preferably located in the incubating enclosure, such being hereinafter described in the The air circulating down through the passageway 44 enters a blower F which impels it through a suitable duct into the lower plenum chamber 3! below the floor in the incubating enclosure.

The rotor of the fan or blower F is coupled to the electric motor 58 through the partition Wall 56 whereby the same motor drives the spray pump and the blower.

The humidity regulating device or apparatus H senses the dew point or humidity of the air and may be arranged to effect its control on such dew point or humidity either by governing the temperature of the spray water, by governing the controlled valve in any well known manner.- The I volume or character of the spray projected, by

temperature of the spray water and the-volume or character of the spray projected. Such humidity regulating apparatus H comprises suitable control means as a part ,thereohwhich control means may be mechanical, pneumatic or electrical g5 in its operation. In the preferred electrical embodiment the rise and fall of dew point or humidity moves a switch 12 into engagement with either of two contacts 15 and 16. When the dew point falls below a predetermined value the switch establishes a circuit through contact 15 and wire 15' to an electric heater 11 disposed in the spray water tank 54. The consequent rise in temperature of the spray water functions to bring the dew point back up to its desired value. On. the other hand, if the dew point or humidity should rise above a predetermined value the switch 12 establishes a circuit through contact I6 and wire 16' to an electromagnetically operated valve I8 which controls the discharge of spray from relatively coarse or large nozzles i9.

These nozzles have branch connection through a tee 8| or other suitable connection with the spray piping 53, 53', and when the valve 18 is opened the major portion of the water is discharged through these relatively large nozzles. Such discharge is a. relatively coarse spray which is not vaporized or picked up by the air stream to the extent that the finer spray from the nozzles 52, 52' is. Hence, with a rise in humidity, the automatic opening of the valve I8 through the circuit connections above described, results in the projectionof a coarse spray in lieu of the fine spray, thereby promptly lowering the humidity to its desired value. It will be understood that the automatic valve I8 might be arranged to interrupt the projection of all spray or a considerable part thereof in the spray chambers for lowerin the humidity, but in such case the valve would be normally open and would close when energized by placing the valve I8 in pipe 53 above the pump and below the branch connections, as indicated in Figure 5A.

The dry bulb temperature of the air is controlled by temperature control means T comprising a thermostat and a suitable switch or other control device for regulating the electric air heater 13. The thermostat T is preferably located in the incubating enclosure I, although it may be situated in the duct leading from the upper portion of the enclosure to the conditioning unit, or in the duct leading from the conditioning unit to the lower portion of the enclosure but for convenience is diagrammatically illustrated outside the conditioner in Fig. 5, although it is shown in Fig. 2 in the incubator. Such thermostat functions with a lowering of the dry bulb temperature below its desired value to switch on or to increase the heating efilciency of the element 13, and to switch off or to decrease the heating action of such element with a rise of the dry bulb temperature, thereby maintaining the latter substantially constant.

The two thermostats H and T are adjusted to maintain a substantially fixed differential of predetermined value between the dew point and the dry bulb temperature of the air, thereby maintaining a substantially fixed relative humidity in the incubating enclosure. The permissible change of dry bulb temperature is confined between closely spaced limits, and. accordingly. if it is desired to adjust the relative hum dity such is preferably accomplished by adjusting the response of the dew point thermostat H, or its control mechanism, whereby the relative humidity can be raised or lowered. In lieu of the electrical heating means 13 and 11, steam heating means may be employed under this same control of the two thermostats H and T, but such heating medium does not lend itself as readily to the critical control obtainable with electrical heating means, and, furthermore, steam heating means requires a continuous source of steam supply. The same is true of hot water heating means.

Comprising part of the conditioning apparatus is an ozone generating machine indicated generally at G in Fig. 5. These devices are well known and need not be described in detail. The ozone is introduced into the conditioning unit through a conduit 86 leading from the ozone machine G and opening into the conditioning unit preferably in the passageway 44 above the blower F. Ozonized air is conducted from the conduit 86 into the conditioning unit at a rate proportioned to have the proper bactericidal and oxygen supplying characteristics suitable for incubating and hatching requirements. In lieu of ozone I may employ formaldehyde or some other bactericidal agent, which is preferably inserted into the system in the conditioning unit, so that the air stream will serve as a conveying and diffusing vehicle therefor.

By compelling such agent to pass through the fan F the same is effectively diffused in the air. The bactericidal agent may be introduced into the air stream through a membrane or porous material.

The operation of the above described embodiment is substantially as follows:-The motor 58 is operated continuously so that the fan or blower F maintains a continuous circulation of air through the enclosure I and through the conditioning unit. The continuously operating pump P also maintains a continuous spray discharge in the successive spray chambers 42 and 43. The conditioned air passing from the lower'plenum chamber 3| up through the eggs heats the eggs in the early stages of incubation and maintains the eggs which are in the later stages of incubation at the proper uniform temperature. A high air velocity is maintained to avoid stagnant areas and the holes 32 in the plenum chamber walls may be of graduating diameters (Fig. 1) to obtain the most effective distribution of air. This air picks up carbon dioxid emitted from the eggs, and also picks up fluff from the chicks, and conveys the same through the upper plenum chamber 26 and through the duct 34 into the conditioning unit C I The fluff is first removed from the air at the screen 48. Entering the spray zone in the region of the nozzles 52, the air becomes partially saturated, and also gives up a considerable part of its carbon dioxid to the spray water by reason of the difference of partial pressures of carbon dioxid between the air and water. Additional carbon dioxid is also absorbed by the lime in the container 58 as the air passes in contact with the same.

Passing upwardly through the other spray passageway 43, the saturation of the air is completed or augmented, and a further removal of all remaining carbon dioxid also occurs in this passageway, the same passing into solution in the water by reason of the difference of partial pressures and the lime content of the water.

It will be understood that the degree of water saturation of the air occurring in the two passageways 42 and 43 will be dependent upon the temperature of the spray water relatively to the temperature of the air and the superficial area of the water drops. The air passing upwardly through the baflies H will have removed therefrom all free water not constituting a part of the true vapor content of the air, and in passing through these baflles the dew point temperature will be sensed by the thermostat H. If the dew point is high for the predetermined dry .bulb temperature or relative humidity, the automatic valve I8 will be opened for reducing the superficial area of the water drops, i. e., projecting a coarse spray, and, conversely, if the dew point is low the temperature of the spray water will be automatically raised by the energization of the electric water heater 11. The air in then passing through the heating element 13 will be heated or not, depending upon the temperature in the enclosure I, as sensed by the dry bulb thermostat T. At a point preferably between the heater I3 and the intake of the blower F, the ozone, formaldehyde or the like is introduced into the air stream from the source of supply G. It will hence be seen that the air returned by the blower F into the lower plenum chamber 3| has all fluff and carbon dioxid removed therefrom, contains a proportion of ozone for bactericidal and oxygen supplying purposes, is maintained at the desired relative humidity for most eifective incubating and hatching, and is likewise maintained at the most effective dry bulb temperature for supplying heat to the eggs in the early stages of incubation and for maintaining uniform the desired temperature of all of the eggs in the advanced stages of incubation.

It is also noteworthy that the present system is substantially entirely enclosed or self-contained in that it always recirculates practically the same volume or charge of air, completely reconditioning the same in each cycle of its circulatiomand, hence, avoiding the necessity of outlets for foul air, intakes for fresh air, etc., with the attendant objections of loss of heat, difllculty of maintaining the proper temperature, and difliculty of maintaining the proper humidity.

Fig. 6 illustrates a modified construction of conditioning unit CI adapted for use with enclosures of the type illustrated in Figs. 1 and 2, wherein a single volume or quantity of air is continuously recirculated through a conditioning cycle. Such embodiment also comprises a main casing lI' having the upper portion of its interior divided into three passageways 42', 43' and 44' by the vertical partitions 45 and 46'. The air enters the upper end of the passageway 42' through the duct 34' leading from the upper plenum chamber of the incubating enclosure. In brief, the circulation of the air through the condition ing unit is somewhat similar to that described of the preceding embodiment, the air passing downwardly through the passageway 42' and upwardly through the passageway 43', in which passageways it is subjected to a water spray, and thence passing down through the third passageway 44' to a fan or blower F which impels the air through a lower passageway 88 to the duct 89 leading to the lower plenum chamber 3|. In this modified embodiment the spray zone is created by a mechanically operating centrifugal water thrower S which draws water from the water chamber 54 and projects the same upwardly in a finely atomized condition in the two passageways 42' and 43' on opposite sides of the partition 45. Said rotary spray device comprises a plurality of impelling arms 92 radiating from a hollow hub 93 which is secured to the upper end of a vertical motor shaft 94, the latter extending upwardly through the bottom wall 55' of the water tank from a vertical motor 58' disposed below the tank. A sleeve 95 extends upwardly from the bottom wall 55' to form a well for the shaft 94, such sleeve extending upwardly above the water level in the tank and having its upper end surrounded by an annular flange 96 within the hollow hub 93, such flange preventing the entrance of water into the upper end of the well sleeve 95. Extending downwardly and inwardly from the hub portion 93 is a conically formed skirt portion 91 having its lower end spaced from the stationary sleeve 95 to form an annular feeding passageway through which water is conveyed upwardly into the hollow interior of the hub. Small discharge orifices 98 are formed in the periphery of the hub, between the impelling arms 92, from which orifices the water is discharged in spray form. The arms 92 may be inclined slightly, like fan blades, for projecting the spray upwardly and outwardly to substantially fill both spray chambers 42' and 43 with a finely atomized spray. The water is sucked up :into the hollow hub 93 from a feeding well IOI, defined by an annular wall in the tank 54' surrounding the lower portion of the hollow hub. The quantity of water vapor projected into the chambers 42', 43' is governed by regulating the rate of water feed from the main water tank 54' to the feeding well IN, and if no spray is desired all supply to the well IN is cut off.

This is effected by a regulating valve I02, which is interposed in a pipe I03 serving to conduct water from the main compartment 54' to the feeding well I0.I.' This valve is automatically controlled in accordance with humidity requirements, as will be hereinafter described. A substantially constant level of water is maintained in the tank 54' by a float regulated inlet generally indicated at I04, and the possibility of the level rising above this'predetermined height is prevented by an overflow outlet 65'.

The spray is prevented from being projected out of the two chamber areas 42' and 43' by baffies 1| extending across the upper portions of both. The air entering through the duct 34' passes down through the baflles II of the first passageway 42' and then encounters a series of fluff removing screens 48'. In this modified embodiment, such screens are arranged in vertically stepped relation with succeeding screens spaced fro each other, and extending across the entire width of the passageway 42. The side edges of each screen are removably mounted on transversely extending supporting bars 49', or upon any other suitable frame structure, and these screens can be cleaned in place or removed for cleaning through a normally closed opening 50' in the front or side wall of the casing H. The spray projected against the under sides of said screens retains the same wet so that fiufl. will adhere thereto. It will be understood that such screening arrangement may be employed in the embodiment shown in Fig. 5, or, the screen arrangement illustrated in such latter figure may be employed in the construction shown in Fig. 6.

If it should be desired to subject the air to the presence of lime for extracting carbon dioxid, a lime tray or basket 98' may be mounted in the passageway 42', below the screens 48', and

in position to be removable through the opening 50'.

The air in passing up through the secondary spray chamber 43' will have all free water removed therefrom in passing through the baflles 'II' at the upper end of such chamber. The air then passes down through the outer passageway 44' and through a lower passageway I06, below the tank 5,! to a centrifugal fan F mounted on the motor shaft 94 below the motor 50'. A horizontal wall I08, defining the bottom of the passageway I06, has an opening therein through which the air passes to the center of the fan F. Said fan is enclosed in a housing portion I09 depending from the transverse wall I08, and the air is impelled from this fan through the housing portion I09 into the passageway 88 which communicates with the duct 89 leading back into the lower plenum chamber of the incubating enclosure. Interposed in the passageway 88 is a heating element 13', preferably electrically operated, through which all of the air must pass before it is returned to the incubating enclosure. Such heater is controlled by the dry bulb thermostat T, as described of the heating element II in the preceding embodiment. It will be noted that said heating element is located on the discharge side of the fan F, posterior thereto with reference to the direction of air flow, so that the-heat imparted thereby to the air can have no influence tending to heat the motor 58' and the bearings of the fan.

A suitable rotary water pump P is also operatively connected with the motor shaft 94. Such pump is preferably arranged within the confines of the fan F, for securing a compact assembly, and has its stationary housing supported on legs II3, which are secured to a removable bottom plate I I4 closing an opening in the bottom of the housing portion I09. This opening is suiiiciently large to permit the fan F and motor 58' to pass down through the same, whereby, when it is desired to remove this assembly it is only necessary to release the impeller S from the upper end of the shaft 94 and to lower the motor and fan down through said opening. Water is drawn from the tank 54' down through pipe Hi to the inlet port of the pump P. Leading from the outlet port thereof is a pipe I H which divides at the T connection II8 into the two branch pipes I I9 and I2I. The latter pipe extends up to a cooling tower CT and flow through this pipe is governed by an automatically controlled valve I23. A return pipe I24 leads from the bottom of the cooling tower back to the conditioning unit CI. The pipe II9 functions as a by-pass in shunt of the tower, connecting at its upper end with a thermally insulated aerator A in which a spraying operation takes place for dissipating to the atmosphere any carbon dioxid or other objectionable gas which has been absorbed by the spray water in the conditioning unit. A return pipe I 24a leads from the return receptacle of this aerator and connects with the return pipe I24 leading from the cooling tower. A spring pressure valve I25 may be interposed in the by-pass pipe H9 and a check valve I26 may be interposed in the return pipe I24 between the cooling tower CT and the aerator A. Hence, it will be seen that when the automatic valve I23 is closed, the entire supply of water from the pump I I2 is shunted around the cooling tower through the aerator A and returned directly to the conditioning unit. When the automatic valve I23 is open all, or practically all, of the pump water is circulated through the cooling tower CT and is then returned to the conditioning unit. The return pipe I24 enters the conditioning unit at a point to discharge upon the fluff screens 48', so that a portion of the return water will cascade down over these flufi screens for maintaining the same in a wet condition and for wetting the fluff caught thereon. A portion of this return water is conveyed laterally through a branch pipe I24b having spray orifices therein through which this water is sprayed down upon the bailles 'II' at the upper ends of both spray chambers. The continuous wetting of these baiile surfaces aids materially in the absorption of carbon dioxid and other objectionable gases from the conditioning air, the impingement of the air against such surfaces resulting in the absorption of such gases in the water.

The cooling tower is preferably situated above the building in which the incubating enclosure is located, or is situated in any other desired location where it will have a free circulation of air therethrough. The pipe leading thereto connects with a plurality of overhead spray nozzles I27 discharging down into a collecting receptacle I28, from whence the water is returned to the conditioning unit through the return pipe I24.

The circulation of air through the spray chamber of the tower is preferably controlled by a thermostatically regulated shutter I29 disposed at one side or end of the tower. This shutter is constructed similarly to and operates like the radiator shutters commonly employed on automobiles, and hence a detailed description thereof is not necessary. The thermally responsive mechanism thereof indicated at I29a is so adjusted that on hot summer days the shutter will open wide for allowing an unrestricted circulation of air through the spray chamber, and on relatively cooler days the shutter will restrict the circulation of air. The tower unit CT functions in hot weather as a 30 cooling device or source of cold for holding the temperature of the spray water in the conditioning unit down to the point where it can exercise the proper cooling and humidifying influence on' the circulated air, thereby avoiding the necessity of refrigerating apparatus for this purpose.

The aeratorA may have a like arrangement of overhead spray nozzles I2'Ia discharging down into a collecting receptacle I28a. However, while this aerator is constructed and arranged so that gases liberated therein are readily dissipated to the atmosphere, the spray water therein is thermally insulated against temperature influence of outside atmosphere. This is effected by sheathing or enclosing the entire device with a porous heat retaining material I30. When the spray water from the conditioning unit is passing through the time) and at the same time'the water is cooled by the atmosphere. In extremely cold winter weather it will usually be necessary to heat the spray water and such is effected by anelectrical heating unit 11' disposed in the tank 54' and having its supply circuit controlled by an automatic switch I 3|. The aerator A as illustrated is constructed to provide limited ventilation to the atmosphere but is substantially heat insulated.

I shall now describe the control apparatus by which the aforesaid regulating operations are performed. Disposed at any desired point in the system is a dew point thermostat H for sensing the dew point of the circulating air. Preferably, this instrument is located in the return air duct 34' or in proximitythereto where it will sense the dew point of the air prior to the air entering the spray chambers 42 and 43'. This dew point sensing device may have different principles of operation .and may be constructed in 'various ways. For example, according to one principle or operation, the air is brought into contact with a relatively cool condensing surface which brings about a condensation of the vapor content of the air upon such surface, and the temperature of this condensate substantially at the time of precipitation is sensed as the dew point of the air.

; tioned in surface area that the precipitation of dew thereon raises the temperature of the coolant approximately to the dew point of the air, whereupon this temperature of the coolant is sensed as the dew point of the air.

Both principles of operation are fully disclosed in the co-pending application filed by myself and Otto A. Labus on November 16, 1928, under Serial No. 319,764, and inasmuch as the details of such device in and of themselves form no part of the present invention, I shall not describe the same here. Assuming the last mentioned principle of operation to be employed, it will suillce to say that a liquid coolant, consisting of water at a relatively low temperature, is continuously conducted through pipe I34 to an externally finned heat transfer coil i35 extending in sinuated or zigzag formation across the lower end of the return air duct 34'. By the precipitation of dew on portions of the surface of said coil, the temperature of the coolant circulating therethrough is gradually raised substantially to the dew point of the air. This coolant is then conducted through pipe I35 to a chamber I31 in which a thermally responsive element I38 senses the temperature of such coolant as the dew point of the air. The coolant is discharged from said chamber through a pipe I39 connecting with the return pipe I24 leading down from the cooling tower CT. The thermally responsive element I38 has any suitable operating connection I, consisting either of mechanical means or a liquid column, with a main controlling contact I42 pivotally mounted on a control switch device I43. Disposed to one side of said contact are two contacts I 44 and I 45, the contact I44 being flexibly or pivotally supported whereby in the initial movement of the main contact I42 to the left a circuit will first be established down through contact I44, and if the motion of the main contact continues in this direction, the contact I44 will be moved to the left for engaging the contact I45 and establishing a second circuit down through this latter contact.

The same arrangement of contacts I46 and I4! is provided on the opposite side of the main contact I42, the contact I45 being movably supported whereby it is first engaged by the contact I42 and is thereafter moved over into engagement with the other contact I41 with continued movement of the main switch contact I42 to the right. Extending from the four contacts I 44 to I41, inclusive, are four wires I44, I45, I46 and I41, the first three of which connect with relays I48, I49 and I50, respectively, the last wire I47 connecting with the relay I49. Current is supplied to the control system through two supply wires I52 and I53, the wire I52 connecting with the movable control contact I42 and also conmeeting with one terminal of each of the three relays I48-I50. The other supply wire I53 connects with other terminals of each of these relays. The specific construction of these relays need not be described, as such are well known.

It will suflice to say that when the relay I43 is energized, a circuit is completed over wires I54 to the heat control switch I3I for actuating said switch to control the operation of the heating element 11'; that when the relay I49 is energized a circuit is established over wires I55 to operate the electromagnetic valve I02 for controlling the supply of spray water to the well IIII and, that when the relay I50 is energized a circuit is established over wires I56 to operate the electromagnetic valve I23 for controlling the passing of spray water from the conditioning unit up into the cooling tower CT.

Relays I48, I49 and I 50 are diagrammatically shownin detail in Fig. 6A and as shown each has a relay electromagnet I48a, HM and I50a respectively which electromagnets are energized when circuits are completed by the main contact I42 of the control switch device I43. These relays have contact armatures I491), I491: and I50b respectively which when attracted by their respective electromagnets engage contacts I54a, I55a and I56a respectively to close the circuits thereby energizing the respective lines I 54, I 55 and I55 from the two supply wires I52 and I53. In addition to these elements relay I49 is provided with a holding armature element I490 which positively retains the contact armature H91: in circuit closing position after the electromagnet I49b is deenergized; electromagnet I49d in this relay, when wire I48 is energized by contact I42 moving to energize contact I41, is energized and thereby withdraws holding armature element I49c and permits armature I49b to retract and deenergize the lines I 55 controlled by this relay.

The operation of this control apparatus is substantially as follows:-When the dew point of the air falls to a particular point, such asa half degree belowthe predetermined desired dew point, the control contact I42 swings to the. left and engages contact I44. This establishes a circuit from conductor I52 through contacts I42, I44 and wire I44" to relay I49, resulting in the latter being energized. Such operates through the circuit I55 to open the spray water control valve I 02 for admitting water from the tank area 54' to the spray well IIII, whereupon spray or an additional volume thereof, is projected into the spray chambers 42', 43' from the impeller S. The tendency of this spray is to bring the dew point of the air back to its desired value. This automatically controlled supply of spray water with a lowering of the dew point may be regarded as the initial or primary corrective operation for bringing the dew point back to its desired value. If this initial corrective operation failsto stop the lowering of the dew point, the control contact I42, in continuing to move to the left, will swing the contact I44 over into engagement with the contact I 45, thereby completing a circuit through wire I45 to the relay I48. The energization of such relay operates through the circuit I54 to actuate the switch I3I and energize the heating element 11' for heating the spray water. Such constitutes the secondary-corrective operation for restoring the dew point to its desired value, such operation occurring when the dew point has fallen say 1 degree from .its de- The switch element of the relay I49 is to constructed that it will remain closed after the control contact I 42 has backed away from the contact I, thereby resulting in the continued energization oi' the electromagnetic valve I02 and the continued supply of spray water to the well It". When the dew point rises, say a half degree, the control contact I42 in engaging the contact I46 energizes the relay I50, thereby resulting in the electromagnetic valve I23 being operated to direct the spray water from the pump P up into the cooling tower CT. Such constitutes the primary or initial corrective step for lowering the dew point, it being evident that the cooling influence of the tower on the spray water will tend to lower the dew point. If the dew point continues to rise, say to one degree above its desired temperature, the control contact I42 swings the contact I46 over into engagement with the contact I41, thereby completing a circuit down through wire I 41' to the relay I49. The circuit through such wire energizes a secondary winding in the relay I49 for moving the switch element to open position, it being remembered that this switch element was left in closed position when the control contact I42 separated from the contact I44.

In consequence, the circuit through wires I is opened and the valve I02 is closed for cutting oil the further admission of spray water to the well I III The resulting subsidance of spray in the chambers 42, 43' constitutes the secondary corrective step or operation for bringing a relatively high dew point down to its desired value, such operation quickly effecting a lowering of the dew point. For extreme inter operation, the circulation up to the cooling tower CT can be shut off by closing a valve I in the pipe I2I.

The dew point control is'correlated with a dry bulb temperature control for governing the temperature of the air. The dry bulb thermostat, diagrammatically indicated at T, is preferably located in the incubating enclosure as described of the preceding embodiment, although it will be understood that such thermostat may be disposed at any other point in the air circuit. A control contact I58, governed by the thermally responsive means of the device, is adapted with a falling air temperature to engage contact I6I, and with a rising temperature to engage contact I62. When the control contact engages terminal I GI a circuit is completed through a relay or directly with the heating element I3 which raises the temperature of the air as it is being circulated back into the incubating enclosure. When the air temperature rises to a predetermined point, the engagement of the control contact I58 with the terminal I62 completes a circuit through wire I64 to energize the relay I50. Such results in the opening of the valve I23 for directing the spray water from the pump P up to the cooling tower CT. The consequent lowering of the temperature of the spray water operates to lower the temperature of the air delivered to the incubator and hence the temperature of the incubator.

Ozone is supplied to the system from an ozone generating machine G which communicateswith the conditioning unit CI at a point on the discharge side of the spray chambers 42' and 43. In the arrangement illustrated, ozone, in the proper proportion, is conducted from the machine G through conduit 86' to the passageway I06, although it will be obvious that, if desired,

the conduit 86' can connect with the passageway 88 or return duct 89.

In summarizing the steps or operations involved in the treatment of the circulating air, as effected by this latter embodiment of the invention, it will be seen that the dew point of the air is sensed by the sensing device H which, through its control apparatus, regulates the humidity by governing the projection of spray into the chambers 42', 43, or, under certain conditions, by increasing or decreasing the temperature of the spray water. The temperature of the air, i. e., its dry bulb temperature, is maintained between very close limits through the instrumentality of the dry bulb thermostat T which, under one condition, effects the direct heating of the air, and, under another condition, efiects'the cooling of the spray water for reducing the temperature of the air. For extracting carbon dioxid from the air, lime may be utilized as described of the preceding embodiment, although the absorption of the carbon dioxid in the spray water will most generally be adequate to remove all of the carbon dioxid content of the air. Such is particularly true in the present embodiment owing to the use of the cooling tower and aerator A.

That is to say, because of the difference of carbon dioxid partial pressure between the circulating conditioning air and the spray water, the water will absorb the carbon dioxid, and then when the spray water is circulated up through the cooling tower CT or through the aerator A the atmospheric air will absorb this carbon dioxid from the spray water because of the difference of partial pressures between the atmosphere and the carbon dioxid content of the spray water. With the giving up of the carbon dioxid from the spray water to the atmospheric air, oxygen will take its place in the spray water within the device CT or A and will be returned to the conditioning system with the spray water serving as the conveying medium. This will follow by reason cf any difference of partial pressure of oxygen between the outside atmospheric air and the conditioned air circulated through the system. Even when no spray is being projected by the spray device S water is nevertheless being circulated through either the cooling tower CT or aerator A, and the return water therefrom projected by return spray pipe I24b down upon the baiiles II provides for absorption of carbon dioxid and other objectionable gases in such return spray and on the surfaces of said baffles. Hence, the continuous circulation of the spraying water through the cooling tower and aerator provides for continuous dissipation of carbon dioxid and other objectionable gases to the atmosphere and the continuous resupplying of oxygen to the system without the necessity of a foul air outlet and a fresh air inlet, whereby the system may be maintained completely closed so that a considerable saving is effected in heating or cooling the air, and a more accurate regulation of temperature and humidity is obtained.

In Figs. 3 and 4, I have illustrated another manner of carrying out my invention, wherein the air supplied to the incubating eggs is handled more or less separately from the air supplied to the hatching eggs.

mechanism actuated by the humidity sensing instrument H; .It will hence be seen that when" hating enclosure, but is partitioned oil therefrom by an end partition I12 and doors I13 closing the sides of the hatching enclosure and opening duit 34' will connect with this separate plenum chamber 26'. Similarly, the return duct 99 may communicate with the lower end of the hatching compartment 1', or may communicate with a separate plenum chamber 3| partitioned oil from the main plenum chamber and communicating only with the lower end of thehatching compartment.

The air circulating through the incubating eggs is handled by a separate conditioning unit, designated C2 in its entirety. As shown in Figs. 3 and 7, such conditioning unit is preferably structurally combined or directly associated with the conditoning unit CI, comprising a single air passageway I defined between the side wall ll of the unit CI and an outer casing wall I16.

The upper end of said passageway communicates with a duct I11 which connects with the main upper plenum chamber 26, and the lower end of the air passageway I15 communicates with a duct I18 which connects with the main lower plenum chamber 3i, whereby the air rising through the incubating eggs is circulated through the upper plenum'chamber 25, down through the. conditioning passageway I15 and back through the duct I19 into the lower plenum chamber 35 for repeated circulation up through the eggs.-

Interposed in the passageway I15 is an electric heater 13" for heating the air. Such heater is controlled by a dry bulb thermostat T disposed either in the incubating compartment of the enclosure, or in the return air duct. Such control may be effected substantially as described of the dry bulb thermostatic controls T, T of the preceding embodiments. Continuous air circulation is maintained by a blower or fan F operatively connected with an electric motor I83, such fan or blower being preferably disposed at the lower end of the passageway E15 for discharging into the return duct I18.

The humidity of this secondary volume of air circulated through the conditioning unit C2 is governed by drawing humidified air from the first volume of air circulated through the conditioning unit Ci. As shown in Fig. 7, this can be accomplished by providing an opening I86 between the return duct 89 and the lower endof the passageway I15, and controlling such opening by a louvre I85 responding to humidity conditions in the incubating compartment of the enclosure.

The humidity sensing in such compartment may be effected by a hygrostat, a wet bulb thermostat, or a dew point thermostat, either being generally indicated at H in Fig. 4, and being set damper I95 may be of any desired electrical or pneumatic type, the element I81 in Fig. '7 repre senting an electromagnetic motor device for actuating the damper under the control of switch the 'inclubating air is at the desired humidity, the .twoivolumes of air are circulated through their respective conditioning units as' separate entities, but when the humidity of this incubating'air falls below its desired value, some of the humidified air from the hatching cycle is transferred to the-incubating cycle to make upsuch deficiency in humidity.

If desired, the conditioning" unit CI may operate exactly as described ofthe construction shown in Fig. 6. In such event, the dry bulb thermostat T would be disposed in the hatching compart-' ment I, as shown in Fig. 4, or in one of the ducts communicating therewith, for controlling the dry bulb temperature of the air, and the dew point sensing instrument H would govern the projection of the spray, the heating of the spray water by the electric heating element 11, and the cooling of the spray water by circulation through the cooling tower CT as heretofore described and shown with reference to Fig. 6.

However, by way of illustrating a modified arrangement, I have shown in Fig. 7 a slightly difierent method of controlling the conditioning operations occurring in the unit CI. The control of the dry bulb temperature of the air is effected in substantially the same manner previously described in connection with Fig. 6, but the control of the humidity is effected in a different manner. The pump P forces spray water through the pipe II1 up to the cooling tower CT, but the 110w of water up to the cooling toweris governed by a valve I89 operatively connected to be controlled by a float I9I. This float responds to the level in the water tank 54', and when such level exceeds a predetermined maximum the float opens the valve I89 for permitting water to be forced up to the cooling tower CT. When the float controlled valve is closed, a by-pass circulation occurs through a spring controlled vlave I92 connecting with a pipe I93 extending up to the spray pipe I93 which discharges down upon the bailies H which are disposed at the upper end of the second spray chamber 49. Thus during all the time that a by-pass circulation is occurring through pipe I93 water is. being sprayed upon these baiiies 1i, and likewise during all the time that water is being returned from; the cooling tower CT, through return pipe I'M, water is also being sprayed upon the fluff screens 48. In such embodiment the cooling tower CT has a relatively large storage reservoir for retaining a large volume of relatively cool water.

The return pipe I24 leading back from such reservoir to the conditioning unit has a regulating valve I93 interposed therein and responsive to humidity conditions in the hatching compartment. This humidity condition may be sensed by a dew point sensing instrument H as illustrated in Fig.. 6, or by a hygrostat or wet bulb thermostat. The control connections between such humidity sensing instrument and the valve I94 may be electrical, as described of the valve I23 in Fig. 6, or they may be of any other desired type. The arrangement is such that when the humidity of the circulating air rises above a predetermined value, the valve I94 is opened for I 

